The Sea Urchin Genome and its Regulatory Gene Networking
The DNA sequence of the purple sea urchin genome, with interpretations of gene function and their networking during embryogenesis is published in a special section of the November 10 Science magazine. The sea urchin is an ideal model system because it readily accepts DNA injected into the egg, and the effects can be observed using a simple light microscope. The overall genome analysis reveals a rich lode of information on gene function, evolution, and embryonic development. Among the more striking findings is that despite a much simpler body plan, the 23,000 genes sea urchin are only slightly fewer than the 26,000 genes of humans. Many of the sea urchin genes have representatives in humans, while there are many others evidently lost during the long evolutionary tract to the primates. With a capacity to digest tough sea kelp vegetation, some of the sea urchin digestive enzymes may also be of interest in broader biomass processing. This study was done in the Cal Tech laboratory of Eric Davidson, with a sub-contract to David McClay at Duke University. A schematic of the regulatory network is included on the large poster in the special section, with complementary audio-visual materials on-line.